We present a new dataset of formaldehyde vertical columns retrieved from observations of GOME-2 on board the EUMETSAT MetOp-A platform between 2007 and 2011. The new retrieval scheme, which has been optimised for GOME-2, includes a two-step fitting procedure that strongly reduces the impact of spectral interferences between H2CO and BrO, and a modified DOAS approach that better handles ozone ab...

We propose a method for controlling a class of low temperature chemical reactions. Specifically, we show the hydrogen abstraction channel in the reaction of formaldehyde H2CO and the hydroxyl radical OH can be controlled through either the molecular state or an external electric field. We also outline experiments for investigating and demonstrating control over this important reaction. To this ...

The singlet electronic potential energy surfaces for the simplest Criegee intermediate CH2OO are computed over a two-dimensional reduced subspace of coordinates, and utilized to simulate the photo-initiated dynamics on the S2 (B) state leading to dissociation on multiple coupled excited electronic states. The adiabatic electronic potentials are evaluated using dynamically weighted state-average...

Multilevel observations of formaldehyde (H2CO) and methanol (CH3OH) toward the nearby spiral galaxies NGC 253, Maffei 2, IC342, M82 and NGC6946 are presented. H2CO was detected in all galaxies (tentatively in NGC6946). CH3OH was detected in all objects with the notable exception of M82. H2CO line intensity ratios point out differences in gas density both between galaxies and within the central ...

Quasiclassical, direct dynamics trajectories, calculated at the B3LYP/6-31G** level of the theory, have been used to study the energy transfer dynamics and collision-induced dissociation ~CID! of formaldehyde cation in collisions with Ne. Effects of varying collision energy were probed for ground state H2CO , and H2CO 1 with excitation in three different vibrational modes: n6 1 ~in-plane CH2 ro...

Quasiclassical, direct dynamics trajectories have been used to study the reaction of formaldehyde cation with molecular hydrogen, simulating the conditions in an experimental study of H2CO+ vibrational effects on this reaction. Effects of five different H2CO+ modes were probed, and we also examined different approaches to treating zero-point energy in quasiclassical trajectories. The calculated...

With a goal toward deriving the physical conditions in external galaxies, we present a survey of the formaldehyde emission in a sample of starburst systems. By extending a technique used to derive the spatial density in star formation regions in our own Galaxy, we show how the relative intensity of the 110 − 111 and 211 − 212 K-doublet transitions of H2CO can provide an accurate densitometer fo...

Results are presented from the first cometary observations using the Atacama Large Millimeter/Submillimeter Array (ALMA), including measurements of the spatially-resolved distributions of HCN, HNC, H2CO and dust within the comae of two comets: C/2012 F6 (Lemmon) and C/2012 S1 (ISON), observed at heliocentric distances of 1.5 AU and 0.54 AU, respectively. These observations (with angular resolut...

ABSTRACT Deuterium fractionation can constrain the physical and chemical conditions at early stage of brown dwarf formation. We present IRAM 30-m observations over a wide frequency range 213–279 GHz singly doubly deuterated species formaldehyde (HDCO D2CO) towards Class 0/I proto-brown dwarfs (proto-BDs). Multiple low-excitation HDCO D2CO transition lines with upper energy level ?40 K are detec...

Emission from the 212 – 111 line of H2CO has been detected and marginally resolved toward LkCa 15 by the Nobeyama Millimeter Array. The column density of H2CO is higher than that observed in DM Tau and than predicted by theoretical models of disk chemistry; also, the line-intensity profile is less centrally peaked than that for CO. A similar behavior is observed in other organic gaseous molecul...